The present invention relates to a closure for a coking chamber of a coking oven in which a door body can be pressed and held in tight engagement with a frame surrounding the charging opening of a coking chamber with sealing means sandwiched between the frame and the door body.
During operation of a plurality of coking ovens of a coking oven installation, the problem arises that during such operation dust, gases and tar-containing vapors penetrate into the surrounding atmosphere. In various countries laws have already been established for limiting such emissions from coking ovens to protect the environment.
One source of such emissions during operation of coking ovens is constituted by the closure means for closing the openings of the coking chambers through which the coking chambers are charged with the material to be coked. Despite considerable efforts it was so far not possible to provide a perfect and lasting seal in the region between the door frame and the door body during the coking operation.
A special difficulty in providing a proper seal of the coke oven chamber in the region of the coke oven chamber closure is due to the fact that the coke oven closure is located directly at the coking chamber head, that is, in a region at which very high temperatures and especially great temperature differences will occur. This will result into bending of the closure parts, which in turn will result in leakages in the region of the closure means and passing of emissions from the coking chamber to the outer atmosphere. Especially the longitudinal sides of the door frame, but also the door body including the sealing means coordinated therewith, will become distorted due to the heating thereof.
It has already been tried to prevent bending of the closure parts, due to the heating thereof, or at least to reduce such bending to a considerable degree, by providing in the door frame an annular cooling channel and passing a cooling liquid therethrough. Such constructions are however rather expensive and the temperature stresses have not been sufficiently reduced by such an arrangement.
In order to obtain a better seal at the door body, a construction has also been developed which includes an endless sealing bar from metal, mounted on the door body, held by friction thereon, but adjustable toward the door frame to engage the latter with a sealing edge. If in such a closure leakage occurs in the region between the door frame and the door body, due to the bending of these parts during heating, the endless sealing bar is moved, for instance by hammer blows, in tight engagement with the door frame. However, even during use of such as sealing bar, which produces a metal against metal seal, the closure of the coke oven chamber with respect to the surrounding atmosphere is not fully satisfying. This is due to incrustations forming on the door frame and the door body and especially on such surface portions of the door frame against which the sealing bar is pressed. Such incrustations are formed by graphite and condensates emanating from the coking chamber and such incrustations can prevent that the sealing bar abuts along its whole circumference directly onto the door frame.
In order to obtain from coking chamber closures with a sealing bar a substantially satisfying seal, it is necessary to remove such incrustations from the door frame, the door body and the sealing bar after each, or a plurality of coking operations. Such cleaning of the closure parts is, however, connected with a considerable expenditure of time. If such cleaning is not carried out by hand, but with mechanical cleaning devices, then an additional large expenditure for providing and maintaining such cleaning devices is necessary. Mechanical cleaning devices are, however, necessary for the cleaning of the closure parts in coke ovens of great height and high operating temperature, in which incrustations of the closure parts occur in large amount, so that considerable expenditures for maintaining and cleaning of the closure parts are necessary.
In closure means with sealing bars on the door body it has also been tried to improve the seal by stuffing glass wool or asbestos into such portions of the closure means at which leakage will occur during the coking operation. This additional sealing operation is likewise expensive and in addition it endangers the health of the operating personnel, since such additional sealing operations have to be carried out during the operation of the coking oven, so that the operating personnel is subjected to the high temperature in the region of the coking oven closure as well as to any emissions seeping past the closure means. Therefore, it has already been tried to improve the seal by constructing a double sealing bar with an asbestos packing therebetween, but even in this way a perfect seal has not been obtained.
Finally it has also been tried to improve the seal by providing in the region between door frame and door body a sealing space into which steam under pressure has been introduced, but a perfect, lasting seal of the coking chamber has also not been obtained with this construction. In addition, such a construction is rather expensive, especially due to the necessary equipment for producing the steam.
A further source of emission is created when the door body is formed with a planing aperture for planing or levelling the material fed in the coking chamber through the opening formed therein. This aperture has to be closed by additional closure means and in the region between the aperture and the additional closure means dust, gas and tar-containing vapors may also penetrate in the surrounding atmosphere. These additional emissions have so far also not been prevented.